The present invention pertains to powered orthotic devices and, more particularly, to relocating powered orthotic devices when the devices are not being worn.
Orthotic systems, such as human exoskeletons, are being used to restore, rehabilitate, enhance and protect human muscle function. These exoskeletons are systems of actuated braces that apply forces to the appendages of an exoskeleton wearer or user. In a rehabilitation setting, exoskeletons are typically operated by a physical therapist who uses one or more of a plurality of possible input arrangements to sends commands to an exoskeleton control system. The exoskeleton control system receives intent commands from the exoskeleton operator (e.g., the physical therapist) and then performs desired actions accordingly. In order to properly execute these desired actions, the exoskeleton control system utilizes a range of sensors placed throughout the exoskeleton to sense the exoskeleton's state. Thereafter, the exoskeleton control system prescribes and controls trajectories in the joints of the exoskeleton. These trajectories can be prescribed as position based, force based or a combination of both methodologies, such as through an impedance controller.
During rehabilitation, although the trajectories of the actuated braces of the exoskeleton are controlled by the exoskeleton control system and commands from the physical therapist to the exoskeleton control system, the wearer of the exoskeleton makes significant contributions to the locomotion of the exoskeleton, particularly with regards to balancing both themselves and the exoskeleton, as well as to maneuvering and turning the exoskeleton. As such, exoskeletons are mostly ineffective or incapable of balancing or turning themselves when not worn by a person. In a number of situations, it is desirable for someone, such as a physical therapist, to move an exoskeleton that is not being worn, such as prior to or after a rehabilitation session. However, the substantial weight and size of the exoskeleton makes the lifting and carrying of the exoskeleton awkward and inconvenient for anyone to execute over even short distances. As the exoskeleton is a locomotive device, the capacity exists for the actuated braces of an unworn exoskeleton to assist in the movement of the exoskeleton. Therefore, it would be desirable to develop a device and method that allows a physical therapist, or other operator, to utilize the locomotive capabilities of an unworn exoskeleton in order to relocate the exoskeleton.